Electric tool



w. MOR ETTI ELECTRIC TOOL Oct. 27, 1931.

Filed June 16, 1928 2 Sheets-Sheet l I I 1 I I A I 1 I I I,

fiTTORNEYS.

W. MQRETT! Oct. 27, 1931.

ELECTRIC TOOL Filed June 16, 1928 2 Sheets-Sheet 2 mi i? 'l atented Oct. 27, 1931 entree STATES PATENT oer-"m1:

-. ,wxlcrrinrnnoiinmai, or ONTAGUE, nassnon'csa'rrsnssion'on ro "MILLER-S FALLS oonreamr, or mums rants, irmsseorrusmms, aconronn'rron or rmssncnoa mm :me'acune is,

" anelectric tool, the operating mechanism of which will beeiiectually housed, but in'Which those parts which should be inspected; re- 'newed or adjusted at comparatively frequent intervals will be readily accessible.

Another object is that of furnishing an electric tool capable of use in numerous dif- Eerent connections, particularly intended to be employed as a drill and which will =be compact in 'construction and light in Weight "so that it 'may readily be manipulated by an -'operator-, and in which, furthermore, the control will be arran ed respect to the other mechanism thereof so that "the tool'may 'be ha nd led with nicetyyand the finished Work will accordingly be free from marring and other errors. J 1 WVith these further --objects in mind, the invention accordingly comprises theieatures of-construction, combination of elements',-and arrangement of :p' arts which will be exemplr ified in the construction hereinafter set forth, mndthe scope of the application of which will be indicated in the claims.

:ofmy application Serial No. 36,142, filed June 10, 1925. I

For a fuller understanding. of the nature and-objects of theiinventionreferenceshould be had to the following detailed description taken in connection with the accompanying drawings, in which:

Figure 1 isa view mainly in longitudinal -cross-section showing'an electric tool constructed to embody the present inventions;

ig. .12 is an enlarged fragmentary View nrncmm :TQOL

1928. Serial m. -285,e'40.

partly .inrasection and partly in elevation showing details of the :switch construction employed :in the s'handle of an electric tool :as'shoiwn inFig. 1;;

Fig.8 is-a iVifiW similar to Q, -hut showing the pants iina slightlynifiermt positlon;

iFig. a is a tragmentary view for .a portion of :zFig, showing sections of certain :pants shown in elevation in.Fig..2'; I

i5 is .a transverse sectional WlQW near the ii'ront end of the electric tool shown in Figgl, takente. illustrate the tan construction employed herein;

'5 is a i fragmentary sectional. View taken onithe line 6- 6 in 4''; Fig. Z7 is actragmentary sectional taken on the :line 27 .in Rig.;2;;

18 is a similar view vtaken the "line 8-8 iniFfigt; Qt;

Fig.'19 zis sawi'ew partly in elevation azmd pa rztly inesectionishoavingiaiside of theswitohri rai me iein-pioyed v.in :the present invention; .2111 i Fig. 16 isa rperspectivevli ewof the sam'e. in the present embodiment, the invention lias been shown as idrill which includes sa casing hawing 1a main ibody 510, to the forfiend' 'ioi :which a gear and spindle head 21:1is preferably detachably secured. ,The rear iend of the-casing isse'xtendecl to provide an integral iheadi13 :and :a handle J14,fthe latter "b eing in'the nature set "What icommonly known as aipistol-grip andiextendingz substantizullyin :line with itheana-in :body :10 of the ousing. This handle is hollow is preferably arranged $30 that its interior may he exposed. A zl his application is a continuation in part Situated t-xuit-hin the interior a of the zcasing :a-ndloclied relatively thereto iis the :fieldmember 21 of 'a motor, and San armature 418 is mounted uponm shaft 219, the outer end of which is fearrieddby a bearingfieihoused Within a suitable recess formed in :the head :lhe inner 'end nf the armature shafit is false carriedi rby *a suitable bearing Q1, and this hearing may :be supported'by :the zhead 118 by forming-rtheclatter with aniinwarellysextend- :collarQQ of ample inner diameter and depth to accommodate 'both the hearing and a paclring member23, which latter serves to prevent the escape of lubricant from within the chamber provided by the collar. The motor brushes 25 are mounted so that their '55 bodies: extend intov openings formed in'.the

handle portion 14, it being preferable that screwcaps 26 may: be employed to retain them in position. v

' i a The head 11 hasan,interiorcontour such as 1 tobe adapted for the accommodationof the v outer-end of the armature shaft l9,'-the spindle orchuck-shaft 7 6 and a countershaft' 77. l Secured to the first of these shafts isa gear78. meshing with a, comparatively large gear 79 secured to the countersliaft 77,'this shaft also; mounting, a comparatively small gear :80,.in turn meshing; with a geari 81 :of i-relati velyf large .size I securedrto the spindle or chuck-shaft 76. Thus a'reduction train '20 is. I furnished .Ewhich -will. increase 1 the torque and; slow down the speed developed by the chuck 82 or other element associated with the :shaft {7 6, and this train is ,soi arranged that 7 its ,components occupy arrelativelyf small 525 amount of space, it"being observed that,-'if

:desired, a suitable bearing'83 may be carried by the extension 84 of the casing, which latter at. this: point provides adequate support for the shaft 76.,

R Theinterior ofthe headwll is preferably packed with; lubricant,-- and in order to pre- Jvent the-escapejofthe' latter it willb'e observed thatLin :the a present instance a a plate :85 isinterposed betweenthe outer edge of. the

' main casing body 10 and a shoulderformed Iadjacent the inneredge'of the head 'This plate has 'ans opening ofample. size to. accommodate thearmature shaft-19,.and obviously serves toprevent the rearward flolwof 10 lubricant into the main z-casingi body.. a To alsoprevent the rearward flow" of this lubricant through'the opening-furnished for the armature shaft and parts assembled there'-. with, the latter may carrya. disk 86, which is c945 :fix'edly secured thereto, at 1a point adjacent the-:rear-faceofethe gear 7.8. and the forward facefiofilthe platen so that the likelihood :ofnthe lubricantbeingforced intothe main casing is reduced to aminimum.

3.750 In the construction 'shown,1n order tocool 'the;motor mechanism,a fan 87 may be cou- ;pled to the shaft 19xat a point immediately adjacent the rear face of the'plate 85, and 3 the casingi 10. at: this point isfformed .with a 1 m radialz series of openings 88throughwhich the/air may-be exhausted; In order that the J airflow may be most eflectual, the fan or impeller 87is mounted within a chamber, one

.a wall of which'is formed by the plate 85, and -Bethe second wall of which,jinithe present instance, is formedby a washer 89 whic h'bears againstrianwannular shoulder formed in the .lIlIlI -;f1Cef of the casing 10- andlis'. retained a T in this position a by "means of springs .9O Zcarm; i dbypins 90;;,-,which are, associated with l 1,s28,9os

the plate' 85 and of asuiiicient resiliency to 1 p i n i a; s t. d nc ibeyondgt V substantially right-angles to the body of i the casing is formedwithan opening orslotrifiO #atit's Pre end, an ndi g. r u ia ld ;;has a hook portion .3 2 WhlChfeIlgflgSl and pivotsupona.cradled-member13 i w i by bendingover the upper sides of 'asup p r ng s p whi h s. e redinet ehan ;example,by means ofthe screws 34c",as -shown ,switch casing 35, 1 form, preferably rectangulanin cross -secmay-be constructed of insulatingmaterial-as ind cated in the drawings. The mountingon ing ndrpthe 'em b iie'; t z wi c i-i am b ie t i a ne 1 forrle ample :by means screws-37;, :1; .3:

I ly in Fig. 10, {comprises 7 a metallic portion 365 wi ah movin parts oaths switchare V attached, and an insulating portion f361'=1to I brushes andfield; ofthe'motorin the usual, a manner.- Thestationary contacts AOJare I ranged tobenbridgedbyamovable contacto :asYindicatedi 3, connects them elec-iv .trrcally III 'SGI'JGSfthG.Circuit being rbrokefi-p therewithe-in thefposition .shown n iga-er I l an opening in the base of the handle' portion l t which conduit is shown as reenforcedi against extreme bending, andyalso prevented from 'relativeinovement atfits point of entry :80

silient material enclosingtheconduit at this E handle, and employing a clamping-member 29 in associationwith the, casing'andbearing gain t t i tube,- Th nn r dg .f" ?1t* portion of the handle 7-14 which; extends a at beyond h s, p n g s: t gge -m mbe comprising ,ashanir 31 ,.of' substantially: 1', U-shape in cross-section in ordertorigidifyi t e s m he upp r en -Of effi ia fi #1 armed dle-portion 14 in any convenient manner,ifr' I j in Fig. 7 Mounted on the memberfitiisa This casing is tubular in' -i tion, having open upper, and lowerends anda j 9 thecasing35 is conveniently effected by grip-1:4; ping 1t. between the switch frameg3fi of the f I switch mechanism thatjs inserted i-n'the :cas-

. a i"- ng secured to theimember34in any-conven-' l the.

which the stationary contactj-members fl are g1 secured,- none, on eachjside. f The stationary r I cOntact-members-AO .serve as {terminals to 126 T- which are secured the conductingfleadsi which: "I conductcurrent fromwthe; conduit 27' to'fthe I i:

41 which,'when it engages-' theiicontacts 40,

whenithe' contactor illis out of engagement imrd 'il he .contaotor 4i zi-szarranged to be actuated lirom rthessharrk 3i! sanyrc nmrniixrt manner by :a quick :acting mechanism, star example, by means of 'it'he ttoggle-imechanism z-shewn compliising the actuating ilGVBI 42 ipivoted in the :Erame mention 36 means of :u, *Jtransxterse "prv'oit 43, whio'h "lever has a depending zarm 44-aengaged by :the shank and a short arm 45 hmvingaatnansmerse iplfi 46 which engages in a :slot 47 ttonmed in 'ithe link 48 ithatisupports fthecontactor 41. The link 48 is preferably of insulating material and has a head 49, between which and the pin 46 there is inserted a resilient member, for example a helical spring 50, which is under compression and causes the link 48 to bear outwardly, its motion being limited by the contour 51 of an opening cut in the insulating portion 36 of the switch-1trame. 'The opening 51 preferably has marginal grooves 52 cut in each side thereof which form guides for the moving contactor 41. These marginal grooves are so shaped as to convey the bridging contactor into contacting relation directly across the stationary contacts 40 when in one position, and to convey a contactor some distance away from the contacts 40 when in the other position.

In order to bias the lever 42 in the open circuit position, a helical spring 53 is coiled about the pivotal support 43 or" the actuating lever and arranged to have the free end 54 bear upon one edge of the opening in the switch-frame 36 through which the actuating lever 42 passes, the other end 55 being arranged to bear against the depending arm 44 of the lever so as to cause it to push outwardly against the shank 31 and thereby hold the trigger mechanism in actuating position, and at the same time causing the short arm 45 to move to its downward position which is below the line of centers for the toggle linkage when the contactor is engaging with the contacts 40. Consequently, it will snap upwardly to the position shown in Figs. 2 and 4.

When the shank 31 is squeezed inwardly by an operator, the depending arm 44 is depressed, thereby causing the short arm 45 of the actuating lever to move upwardly until it is above the line of centers of the toggle linkage, whereupon the contactor 41' is caused to snap downwardly into engagement with the contacts 40.

In order that the operator of the tool provided herein need not continually press upon the shank 31 while the tool is being operated, a locking mechanism is preferably provided which holds the shank 31 depressed for as long a period as it is desired to operate the tool. The locking mechanism, as illustrated in Figs. 1, 2, 3,4 and 6, consists of a sliding member provided with a depending actuating portion 61. This sliding member has a wedging portion 62 struck up therefrom at in the'znormarl position, abut to permit ;it to 7 islide in between =the :shank 3:1 and the inner zp'ortion :oi the ihandle 14, as indicated in 3, when the trigger mechanism-1 s the '1l6}7l55fi8d :pesition. the shank .34

azelceased, auiterzthezslidingrmembenfimhasiheen :meved to the YPOSlfilOH show-n in Fig. 3, {the sslidingnnember :isigripped -between the upper endrof :s'hank31 and the inner side of :handle .14 :and is held frictionally :in @StlGll position asrlong as .it .iisidesired to "operate the tool. 5

it is {desirable to have the sliding member automatically sresume its nominal position when it is dGSlLQCllbD'StQP the 13001. 'To 'this end, a spring 53 is provided :to react. against rthe .slidjaig member when moved to .theposirimn showm Rig. 3. @This spring-is preferaibly 'c'eiled 1 about a proj ectingrtongue 64 on slid-ing member and bears against the main :portion =60kof the sliding member :for one abutment zand' against a stationary ,prong as the other :ahutment. This prong is rpreierahtyozarnanged, :in .addition, to serve as a guide for the tongue 64 and comprises an extension of f3 supporting plate -i6 that is secured 'to the supporting member (34, :as

Fig.4. It :isthus seen thatrthe-slid- :ing member is normally retained in the vshank disengaging position but may be i momediby the :pressu-re of a fingerof an oper- ;a:tor :into engagement with theshank when filQIlI'BSSGfiiZO actuate the switch mechanism to close 'rthe circnitthrough the anotor, this sliding member then being zf rictionally retained between the upper end 04 the shank :and :the

."iIHIQI side of the handle 14'80 that the switch mechanism irem ains an icircnit elosed position. When it :is desired-:torstop the \tool, the woperator-ragain presses inwardly slightly npon the shank 31 so :as to remove :the ifIlCfilOIl-Q'l engagement-between the upper end oitnthevshank randthewedging portioni62 whereby the resil yient member 64 operates to more :the sliding member to its normal position so that when the workman releases ;his pressure upon the shank 31 the-circuit is therebyfapened.

Ellhe vhandle .14, :bBSlClBS housing the switch -mechanism above described, is adapted also to house connectors iorzother convenien-t cir- :cuit controlling devices such as the cartridge rcleuice shown at intheidrawin gs.

Sincenertain changes maybe made in the :above construction vrand difi'erent embodi- Qments (of the invention could be made with- -on't departingfrom the scope;.thereo, it is intended that all matter contained 'in rthe' 33o above: description orshown in 'theaccompany.

ing drawings shall be interpreted as illu tiveand'not in a limiting senses:

V H ving 2 described ..my.%.l invention, what; I claim :is new and desire to. secure by Letters Patent is: v

' 1. Inan electrictoolhaving a handle portion' including a hollow pistol-grip, the combination with said=pisto1:-grip, 'ofsa trigger member pivotally. mounted'therein and exv tending along said grip,'a'switchsupporting i f frame disposed in' saidi hollow. portionra'nd V "removably secured in said grip, a pair ofrstatio'nary contacts on sa1d -frame,}a contactor 5 guide: inf'said frame, movable: contactor. i mounted-to move on said guide into and out ofa bridgingposition across said contacts, a snap-actuating lever mounted on said frame 1 normalxposit'ion when the frictional engage- .ment I between said trigger member and said Irioving'portion of said trigger m mberand 'saidhandle portion so as to retain said trig-l ger member in depressedlposition byi fricr tiona-liengagement.therewith; and. resilient means bearing against said sliding member and adapted to cause-the same to move to handle-portion isremoved. I i r W ln'testimon'y 'whereofIafiix my signature extendinginto engagementwith said trigger p I V I v l leading fro'm a'source of. current tofsaid tool. 2. "111 an electrictoolliavinga handleportionincluding'a hollowpistol-grip, the 'com- 5 'bin'ation withsaidjpistobgrip, of-a trigger 'member pivotally mountedYthereinand i'extending along'saidl gripm switch supporting frame disposed' in- -saicl'hollow 'portionand p removably' secured in said grip, a pair-of "stationary contactson said frame, a-contactor guide insaid frame," a moVablei contact0r mounted to move on saidguideiinto and out of abridging position. across said] contacts,

"extending-into engagement with saidtrigger member,and'a"slidingflmemberfhaving an 'engagingr portiongadapted to be moved into and out of Weclging':engagement ivithsaid "trigger member andxsaid handle,twhereby i- V Whe'nsaidtrigger is depressed and the'sliding 1 member is in engaging position .said trigger tinnedpressure from the operator H 1;

" 3; Inanelectric cool,the combination'com "prisinga handle-portion,v a trigger member and a switch member -adaptedtocloseaneleci memberjand electrical connections disposed Y 7 "in said 'grip'conn'ectedwto sald-icontacts and a snap-actuating lever mounted on saidxfranle i jis retainedind pressed position withoutconi tupon h vement-inf said trigger '1' f ,-member, and a,- shdmg having} an V engaging portion adapted to slide into L'Wedg 111g engagement-With said trigger-member Q and said "handle wh'e'reb'y when said trigger member is depressed and the" slidingmember "moved into en'gagement there-With it"may be I-LQ retained in said depressedi positionwithout 5 continuedpres'sure front-theoperatorfig;

Y '4 In an electric tOoLthe combination com- V "prising, a handle-portiom" a' trigger member pivoted therein aswitch mechanism in'sa-id Q I: f v.

handle 'po'rtion adapted to bea'ct'uated bysaid trigger membe'rto make and break an electric j '1 *Qircuit; and a-sliding member adapted to slide I "between a relativelymoving "portion 0fsa-id':''*

trigger member and'said handle-portion, said i sliding 'member having a'wedging'portion; r i

' adapted toxintervene-between said relatively r ill I 

